Posted
by
CowboyNeal
on Saturday March 31, 2007 @09:07AM
from the gloom-and-doom dept.

An anonymous reader writes "Patrick McFarland, famous Free Software Magazine author, has written a two part article about why Powered USB is not taking off at home. (part 2 is also available) He includes a lengthy history on why USB took off in the first place, and then continues on to explain what we gain by allowing Powered USB to power all our devices."

Agreed.I've never been a big fan of USB. The concept is fantastic, a unified connector that links just about any device to any other and can charge them is a great idea. However I am still bitter the Firewire lost out. It has more bandwidth, has sturdier connectors, and can deliver far more power. Being able to just plug one cable to power and link a hard drive would be great, I have one of those external IDE enclosures, and having *another* power brick is just silly.

Being able to charge high draw devices through Firewire would rock. Powering my laptop from my PC would be great, especially if it will be syncing files at the same time, allowing me to leave the power brick in my laptop case and not have to get it out after getting home.

In my eagerness to get this post in first, I didn't read the article before I started typing. He says it all the same way I would. So to all of you who haven't RTFA'd, do it to find out the rest of this comment's points. Now lets see if I can still get this in first...

I've got a 2.5" external drive case that uses two USB wires. One goes to a standard USB plug on the case, and the other goes to a connector that's just a power socket. Standard USB supports a given amount of power per connector, so this is getting around the limitation by doubling that. (Obviously you need a powered USB hub or direct connection from a computer, not a non-powered hub, and calling the new version "Powered USB" seems like an unfortunate naming collision.)

Using two cables kind of defeats the purpose. The whole point of the exercise is to only have one cable, transferring data and power. I have a twin-cable too, but it is unusable on my laptop that only has one usb-port on the side and one on the back.

True. Actually, there were very, very few Firewire enclosures that could power a 3.5" drive. Actually, the only one I've seen was from Weibetech and they discontinued it. Those enclosures were too expensive. The 2.5" drives are too slow and low capacity to justify using just to save a power brick in a desktop situation, for mobile needs, a 2.5" drive is almost necessary, the 3.5" drives were usually too big.

American Media Systems (http://www.american-media.com) produces 3.5 inch and 5.25 inch external USB and Firewire enclosures that have internal AC power supplies which at least gets rid of the power brick problem. They recently revamped their web site with Flash unfortunately.

I have three of the older AMS cases which are quiet enough but the original fans did need to be replaced with higher quality ones. I am not sure about the newer enclosures but the old full sized ones conveniently have a standard 120 volt AC socket on the back chained with the IEC input. They are also designed to stack which some of the slimmer ones discourage by being oddly shaped.One of the reasons external power bricks are so common is that they make UL certification easier.

At Frys they now sell a USB to IDE drive adaptor that is a 'molded cable' adaptor for attaching an 'out of the case' 2-1/2" Hard Drive to your machine. Very handy for transferring data from drives that have been pulled from a laptop, also good for 'injecting' stuff onto drives you're going to plug back into a laptop. The adaptor nicely powers a typical 2-1/2" laptop without any difficulty.It's the same 'guts' as used in those cheap aluminum USB 'laptop drive' external housings, which also get their power

Hi, I'm the guy who wrote the article in question. Yeah, I had laptops-charging-while-syncing in mind as well when I wrote the article, its only a step up from PDAs who charge while syncing (which already is done via normal USB on some PDAs).

I'm a fan of Firewire as well, which is mainly why I wrote this article in the first place. Powered USB handles all the power issues (except for the flaws I noted in my article), and a future USB 3.0 revision will catch USB up to Firewire 800 over 9 pin cables (as opposed to the new over-CAT5 and over-Optical versions that are really for special use applications and completely outside the realm of desktop computing), so I just don't see why they don't clean up Powered USB and either integrate it into USB 3.0, or release it as a more official optional extension.

USB may have killed Firewire, but that doesn't mean USB is ready to replace it quite yet; the fact Firewire 800 was even released, and supported on non-Apple devices pretty much proves that.

If I could pass back one comment on the article, there seems to be a few grammatical errors in there. The article itself is very interesting but poor grammar detracts from its impact.

By 2000, some computers were not shipping with hardly any legacy ports at all

That's not just a double negative, I don't think that even makes sense.

I will tell you why Powered USB will never be widely excepted

I'm sure you meant accepted there.I apologise if I come off sounding like a grammar nazi but I find it difficult to read an article and take it seriously when it is presented in this way. That aside I would completely agree with you on the point of powered

Actually, I'm with on of the comments to the article on your site: Increase power efficiency.As an example, I have a USB-powered Canon color scanner (one of the things you mentioned that can't be powered as such) and it works great. We have global energy issues anyway, and I'd rather provide a constrained amount of power than a firehose through which every device can suck as much as they want.

Further, many of those devices connect to notebooks which have limited power budgets. More efficient use of power me

Agreed... but I think a balance is necessary - increased power efficiency, but there are some devices and applications that need more power than the standard allows.

A typo? I have a 17" MacBook Pro that supports FW800 just fine.Not a typo... poster was only referring to the fact that many PC manufacturers don't include add-ons that most people never use. Mac's having this hardware is the norm, for PCs, it is not. For a PC to have it, it means that it is at least gaining some common use.

Looking at the design of the port, it appears to add four more pins exclusively for power. So why the "one voltage" limitation? Even if you reserve one pin for a redundant ground -- the USB data cable and power cable may be connected to two different circuits on the device end -- you should still have enough connection ability to run three voltages in addition to the 5V in the USB data cable.+12V seems like a no-brainer since the world is overrun with devices designed to operate at 12V. -12V also seems usef

Why the heck do you need more than one voltage anyway? Why do you even need a different plug as well? If it where me I would have the devices negotiate extra power and if both say good to go, stick it as a DC offset of 48V on the data lines. The device on the other end can easily do DC/DC conversion to get whatever voltage it really needs with very high efficiency.

Powered USB will not fail. It is already a success - in the Point Of Sale market for which it was intended.The reason why the USB-IF did not adopt this is because of IBM's patent schticks. Without this issue they probably would have ratified the 12v version for general consumer use. The other voltages would have remained specialty items for the POS industry that normal users would never encounter. The multiple voltage versions make a lot of sense for the tightly integrated and cost-sensitive POS market.

I think one of the big reasons that Firewire caught on was soley because of DV video cameras. DV is going the way of the dodo within the next 5 years or so to be replaced with disk based and flash based recording systems. When that takes place. Firewire will in my view lose about 3/4 of its market.

Perhaps not on the Mac front, but definitely on the PC front where USB is so much more prevalent except for capturing video. For highspeed HDDs expect eSata solutions to prevail.

I think there might even be three. The 'typical' one most people will recognize, the new one (FW 800) that was on some G4 Au PowerBooks, and the mini one often found on DV cams (and that Sony in particular put on their laptops).

Apart from being not stable, it's also doesn't carry power I believe (like the small USB interfaces). New power interfaces (like those on the Nokia charger) are incredibly small. I'd like to see an small interface designs in future (for USB or IEE1394) be able to deliver power too.

They are 6-pin (larger and powered) and 4-pin (small, unpowered) on FW400. This is because consumer/prosumer cameras have space constraints and run under their own power. Sometimes manufacturers (Avid, e.g., ugh) use 4-pins on non-portable devices, just because they're powered, which sucks, because you're absolutely right, the 4-pin firewire jack is easy to ruin with a little jiggling. FW800, however has a medium-small but pretty stable plug and jack.To be fair, USB has a range of jack sizes too, including

Firewire wins over USB 2 any day if you want stable bandwidth and CPU load (e.g. video), and the option of fast networking.

I broke my Mac Mini's Ethernet adapter (while I was waiting for DSL in my new place after moving house I was using the modem in the Mac Mini to share out a 56k connection, but stupidly plugged the phone cable - the RJ11 jack is right next to the RJ45 jack on the Mini - into the wrong place one day). This fried the RJ45 port it seems (unsurprisingly), though thankfully the Mini is otherwise fine.

I've been using the Mac Mini to manage my media, particularly my MP3 and Video collection, and that's stored on a

I gotta say I've seen RJ11s plugged into RJ45 plenty of times (including a computer lab in a middle school where the resident technology guy was paid 6 figures and set up the whole lab of new iMacs using the phone cable that came with them to plug them into the ethernet network). I've never seen an ethernet adapter damaged by it. It is a common mistake by the exact market the Mac Mini is aimed at, I would expect the adaptor to be more hardy then that. Unless your phone line has much higher then normal vol

It is a common mistake by the exact market the Mac Mini is aimed at, I would expect the adaptor to be more hardy then that.

It does seem like bad design on the part of the Mini (given a lot of people will be reaching round the back to plug it in without really looking where it is).

Unless your phone line has much higher then normal voltage on it or something, I'd suspect there was more to it then that, and I would suggest calling Apple about it. If plugging a phone line into the ethernet port is enough to make the port unusable I'd have to say Apple has a pretty serious issue on their hands.

The port was working right before, but not right after. I seem to recall I was re-connecting it because I I'd just moved the mini across the room - and that it even cause the mini to reboot when I did it (which caused me to go "WTF?" and then actually turn it round to see what I'd done). It doesn't recognize anything as being plugged into the RJ45 po

i've never seen an ethernet adapter damaged by it.i don't know how recent your experiance is but you should bear in mind that gigabit gear is far more likely to be vulnerable to this as the middle pair (which is usually what is used for phone connections) is an active data pair in gigabit ethernet.

phone lines use non trivial voltages (about 50V dc open circuit, less when loading by an off hook phone far more when ringing), while they aren't anywhere near as brutal as a properly built etherkiller (note that

Thanks for the info, I'll admit my tech support days are behind me, and I had not considered gigabit might be more vulnerable. I have not had to use the modem on my laptop, but I will be sure to check more carefully what I plug it into. I will say that hopefully most consumer equipment has taken steps to limit damage, considering it is a common mistake by novice users (and considering the similarities in the connectors and their functions an understandable one) and sometimes absent-minded professionals.

That's a cool story. I've used a firewire cable with my laptop in a pinch at various times when a spare ethernet cable wasn't available, and it always works easily (mac/linux, haven't tried it with windows yet). I'm curious about real-world throughput speeds on an IP network, if anyone knows. It's a little-known feature, it seems. Does anyone else have a permanent setup using firewire?

I'm also curious about why it's so easy to do this with FW and not USB.

Agreed.I've never been a big fan of USB. The concept is fantastic, a unified connector that links just about any device to any other and can charge them is a great idea. However I am still bitter the Firewire lost out. It has more bandwidth, has sturdier connectors, and can deliver far more power. Being able to just plug one cable to power and link a hard drive would be great, I have one of those external IDE enclosures, and having *another* power brick is just silly.

One thing the author of the article missed is the original purpose of parallel and joystick ports. They were called "parallel digital input/output port" and "scientific port". The parallel port was meant for general purpose digital I/O (so you control relays or tell whether a contact is closed or not) and the scientific port could be used to connect thermocouples for example.

These were "starter" ports that made the computer useful in the lab or in the factory without purchasing additional components. Nowadays a special expansion card or external device are necessary to get back the same capability. The cheapest are around $100, but this quickly ratchets up to $1000 and more for anything capable.

One thing to keep in mind is that the original IBM PC (which was before XT and before AT) had a fairly slow processor (6 or 8 Mhz ? - can't recall) and the audio-range sampling rates of parallel port and joystick port matched them well. Nowadays we have Ghz cpus, but anything that captures faster than 100 Mhz is expensive - with Ghz cards costing more than the cost of the computer.

Nowadays a special expansion card or external device are necessary to get back the same capability. The cheapest are around $100

You're correct, but to be fair in comparision, back when those ports were popular on the IBM-PC, the parallel, serial, and joystick ports were themselves expensive add-on cards.

The PC and PC-XT had NO built in I/O. You had to plug in EVERYTHING as expansion cards, includng floppy controller card, hd controller card, serial card, parallel (which you could get built on with the MDA monochrome text-only video card), game port card, video card. None of these were built in 'on the motherboard.' On the original PC it wasn't hard to tie up all five expansion slots, since you also didn't get 640K on the motherboard, so had to plug extra RAM in _brace_yourself_ an expansion card in other I/O slot.

Thus the rise of the 'AST Six-Pack' and other multifuntion cards, which gave you seral/parallel/memory/realtime-clock/etc. all on one card (a card that cost about what people pay now for a whole system at Wal-Mart.)

While firewire is spec-wise superior to USB it is also a major CPU hog since majority of its translation is offloaded onto CPU. Case in point, try running external fw soundcard on lower latencies and you can say bye-bye to >=1/4 of your CPU cycles. USB does not have this problem.Regarding powered USB, I think it is alive and well. Creative Zen players recharge that way. I also had purchased at one point laptop HD enclosure which offers both USB and fw. USB runs just fine off of USB power coming from my

I think you have it backwards, unless you have a PC or FireWire Card that doesn't support bus master. It is not uncommon to find marginal FireWire support on PC's, but most consumer & pro electronics, as well as all Apple products offer full Firewire support.

USB requires a host CPU; FireWire does not.

FireWire uses a "Peer-to-Peer" architecture in which the peripherals are intelligent and can negotiate bus conflicts to determine which device can best control a data transfer

USB 2.0 uses a "Master-Slave" architecture in which the computer handles all arbitration functions and dictates data flow to, from and between the attached peripherals (adding additional system overhead and resulting in slower, less-efficient data flow control)

USB 2.0

1.5 Mbit/s 12Mbit/s 480Mbit/s supported.USB controller is required to control the bus and data transfer.Cable up to 5 m.Up to 127 devices supported.Power supply to external devices is 500 mA/5V (max).Full compatibility with USB 1.1 devices.

I tend to find devices that charge via USB annoying. I don't leave my computer powered on 24x7, and maybe I want to charge my mp3 player for an hour without having to boot up a computer (that draws 30W+) to charge up an mp3 player that probably needs 50mW.

I'm sure that somebody sells an USB-AC adapter for such things, but what is wrong with just putting a standard DC power adapter on the device?

I have an old USB 1.x hub that I use solely for charging, since I have six USB 2 ports (four in back, two in front) already. Were it not for this purpose, it would be gathering dust in a drawer.

If you are inclined to do a bit of wiring, re-purpose one of the USB connectors that came with your motherboard (since you are probably using those that came installed in your case) and run 5V power through the red and black lines. You now have a standalone charger.

Agreed.I've never been a big fan of USB. The concept is fantastic, a unified connector that links just about any device to any other and can charge them is a great idea. However I am still bitter the Firewire lost out.

I'm not aware of a major standard failing in the past because some random guy (sorry, no offense) was "bitter".

USB always makes me struggle which way to put the connector in. Firewire is a little better, but still, you'd think that the people who make connectors would be able to come up with either a connector that makes it obvious which way it goes in, or one where it doesn't matter how it goes in.

like offloading work from the cpu as the older and slower fire wire 400 bus is faster then the usb 2 bus and it can be used to link 2 systems together with out a special cable

I don't think USB will ever support peer to peer. USB 1.0 was designed to have a smart host and dumb devices, to make sure that low end Asian manufacturers could make mice and keyboards with a couple of man-weeks of labour, probably only a few man hours once they get up to speed. Later on people started to use it for storage, and USB 2

You can sort of fake peer to peer with USB. For example, a device that is 2 USB devices that look like network or serial devices back to back in a device. It's not REAL peer to peer since the host can't use that to mediate direct data transfer betwen (for example) a storage device and a printer, but it's close enough for most people.

I fully agree that it was a decent tradeoff for the bazillions of sub $30 devices that resulted from an easy to implement standard.

I don't feel that computer designers should really have to think about some peripheral device sucking 50 watts out of a connection on the motherboard. If you want power, get a cord. If you want portable power, bring a battery. Just having one fewer cable on a desk is not a problem worth solving this way.

Laptops, for instance, are designed around very limited power budgets. If you plug a 1000 watt USB hair dryer into it, how long are the batteries going to last?

A solution I would be in favor of is building lower power peripherals. Building 500 GB flash hard-drive replacements than run on half-a-watt should be possible in a couple of years. Building very low power OLED displays should be possible. Building low-power devices is something that is a win in every possible way, and should be encouraged -- the USB power limitation is a great way to stimulate this!

That said, I'm really sorry I passed up the USB-powered heated typing gloves I saw in Shinjuku last fall...

I don't feel that computer designers should really have to think about some peripheral device sucking 50 watts out of a connection on the motherboard.

Why not? Sure it's another factor in motherboard design, but as long as the USB peripheral and the controller can negotiate the power demands, then it's easy enough to make sure it's not going to burn anything out. If a device would draw more power than the mobo would supply, the controller simply wouldn't power it. That would make USB-deliverable power another feature by which to compare mobos.

Just having one fewer cable on a desk is not a problem worth solving this way.

I disagree. Perhaps I would agree if it were only one cable, but it's not. It's often four or five cables. My desktop, for example, has two printers, a scanner, speakers and a monitor, plus the CPU, so that's six power cables and six data cables (including the network). Worse, the six power cables require two power strips (because the wall warts cover more than one outlet on a typical power strip), so there are an additional two cables, for a total of 14 cables under my desk, for that one computer. Powered USB, if done right, could conceivably eliminate both power strips and all but one of the power cables, so instead of 14 cables, I'd have seven. Even better, the routing of the seven would be cleaner, since all of the peripheral cables connect to the computer and the compute is the only one that connects to the wall. That's well worth doing.

Laptops, for instance, are designed around very limited power budgets. If you plug a 1000 watt USB hair dryer into it, how long are the batteries going to last?

Not long, of course, but if I want to do that, and if the laptop can deliver the juice (unlikely in your example, but we could construct another that was more feasible), why shouldn't I be able to? They're my batteries and the power in them is mine to spend as I please.

A solution I would be in favor of is building lower power peripherals. Building 500 GB flash hard-drive replacements than run on half-a-watt should be possible in a couple of years. Building very low power OLED displays should be possible. Building low-power devices is something that is a win in every possible way, and should be encouraged -- the USB power limitation is a great way to stimulate this!

Given the increasing move to portables and the apparently-insurmountable limitations of batteries, I think that problem takes care of itself. Low-power USB-powered devices would have an inherent mobility advantage that would drive their sales over hungrier devices. They'd also be cooler and quieter, which also tends to please buyers. There's no reason to impose an artificial barrier which makes classes of devices that can't quite reach the 0.5A mark completely infeasible.

Why not? Sure it's another factor in motherboard design, but as long as the USB peripheral and the controller can negotiate the power demands...

Because the power demands aren't just on the motherboard, but on the power supply. The motherboard typically doesn't know the capacity of the power supply. Even allowing that it did, an over-large power supply is less efficient than one sized right for the most typical use of the system (assuming they are otherwise power supplies of equal quality).

To add to that one of the big benefits for travelers is the need to take only one adapter. Since my cell can charge over USB, I don't need to take my cell charger and adapter to make it go. Much much much less space!

"Perhaps I would agree if it were only one cable, but it's not. It's often four or five cables. My desktop, for example, has two printers, a scanner, speakers and a monitor, plus the CPU, so that's six power cables and six data cables (including the network)"

So? Work smarter. I have a 17" Apple MacBook Pro on my desk and it has exactly ONE cable connected to it: the MagSafe power connector.

The mouse I use (when I use one) is Bluetooth. My printer and speakers are plugged into an AirPort Express across the room. A 500GB hard drive and the big HP color laser are plugged into an Extreme in the next room, which is where the DSL line comes in and besides, it's quieter that way. Backups to the HD, while slower, are scheduled and occur in the background, so who cares how fast they happen? The network is obviously wireless, and 802.11n due to the Extreme.

I have a USB-powered Canon scanner, and I plug it in when I need to scan something (rare).

The Apple AirPort Extreme and Express are great options, and work on Macs and PCs. I think Belkin also has a wireless USB hub for PCs.

So? Work smarter. I have a 17" Apple MacBook Pro on my desk and it has exactly ONE cable connected to it: the MagSafe power connector.

Right, so you get rid of some cables at the expense of accepting a small, low-resolution screen with limited contrast and small, slow data storage. Not a good tradeoff for me, at least (as compared to the 23" 1920x1440 CRT and striped 320 GiB 3Gbps SATA drives on my desktop).

If a laptop can accomodate your computing needs and fits into your budget, then certainly it's a good way to eliminate (some) cables.

My printer and speakers are plugged into an AirPort Express across the room.

Which means you haven't gotten rid of any of those power cables (or the power strip, most likely), you've just moved them away from your desk. Not a bad thing, certainly, but not as good as eliminating them. Now imagine how clean it would be if the AirPort Express supported powered USB devices, and your external drive and printer ran from that.

Also, I should point out that my LAN is GigE for a reason. I move a lot of big files around and even 100BaseT is annoyingly slow (I can't saturate the GigE, but I get transfer rates about 3x as fast as 100BaseT could handle). I have an 802.11g WiFi network, but even my laptop is plugged into the GigE when I'm at my desk, because WiFi is just too slow when you need to move data.

I have a USB-powered Canon scanner, and I plug it in when I need to scan something (rare).

So there are two more cables on your desk, though one of them isn't typically attached to your computer. Again, powered USB would eliminate one of them.

The Apple AirPort Extreme and Express are great options, and work on Macs and PCs. I think Belkin also has a wireless USB hub for PCs.

Certainly, if they work for you and if you don't mind paying for them. Also, I don't think they work for Linux, except for the music playing option (I'd like to be wrong here!). They don't, however, really remove the need for cables so much as allow you to spread the cables around a little more. That's not bad, but it's not as good as eliminating them.

The MBPs screen is 1680x1050, not exactly low-res, and has a 160GB internal drive (probably get a 300GB internal this summer), and the wireless net is 802.11n, not 11g. My DSL connection is 1.5mbs, and I can't saturate the net. The Canon scanner is USB 2.0 powered, as I said, so it has already has one cable, not two.At any rate, much as I'd like to zap the bricks I'm against even more incompatible cables and ports. Perhaps if there was ONE powered USB standard and not three it would make more sense, but eve

It's marginally acceptable resolution but it's still small and low-contrast. However, I have to give on this point, because my CRT couldn't be powered off of USB anyway, since it draws up to 200W according to the UL label.

160GB internal drive (probably get a 300GB internal this summer)

Still too small for me, and much slower.

My DSL connection is 1.5mbs, and I can't saturate the net.

Well, sure, if you're surfing WiFi is just fine, and 802.11n isn't too bad for now, since it is only ~70% slower than most hard drives. All assuming you don't have any problems with interference, of course. If you don't, good for you, and ke

First problem is that no laptop, and no consumer desktop, would be able to power all of that off their power supply. A laptop couldn't power a CRT, and most decent sized external LCD panels, on their power brick. You are demanding a computer be a power distribution system for external peripherals, and that is stupid as their are designed today. Being able to power a mobile printer, any reasonable external storage, a VOIP phone, etc, would be very useful. Fortunately, we *already can do that*, so it isn'

If a device would draw more power than the mobo would supply, the controller simply wouldn't power it.

Yes, that's exactly what we need. Besides training Grandma to iterate (she can't read the tiny markings) through the 5V, 7V, 12V, 14.2V, 18V, and 24V identical sockets to find the one her new USB-Laserjet's plug will fit, we field the support calls about how her mouse and hair dryer sometimes shut themselves off at random when she prints. Granted, a proper power negotiation would kill (deny power requests t

It's often four or five cables. My desktop, for example, has two printers, a scanner, speakers and a monitor, plus the CPU,

Your CRT (or even mid-large LCDs) aren't a candidate for USB power, unless USB starts requiring cables and connectors as massive as power cords... Even then, it's not likely anyone's going to want ultra-massive PSUs and motherboards to support that kind of power draw.

Printers and scanners aren't very good candidates either, as they have high power requirements, and high surge current.

Ability to use the same USB device with either a low power notebook computer or a desktop system is what USB is all about, and a strong case against powered USB. The deliberately low power limit is what makes USB universal: the peripherals work on any system, big or small, battery powered or cord connected.

There are also cable design issues with increased current levels. The wires must not over-heat or lose too much voltage from the conductor resistance. The USB cable connected to the system at my right ha

Laptops, for instance, are designed around very limited power budgets. If you plug a 1000 watt USB hair dryer into it, how long are the batteries going to last? A solution I would be in favor of is building lower power peripherals.

The issue is how much nicer it would be to be able to run and charge devices with more than 2.5 watts. I'd love to be able to plug in my music player or cell phone and have it charge up quickly without needing to find or carry more than the plug to my laptop. As it is, my mu

I don't feel that computer designers should really have to think about some peripheral device sucking 50 watts out of a connection on the motherboard

The motherboard doesn't have to be changed. Your power supply already generates 5V and 12V for all the peripherals in your computer. So you can have the USB part of the connector soldered on the motherboard, with a connector going directly to the power supply. That's really not a big deal.

I love the idea of those USB power strips. Imagine being able to power your notebook off of one! That could end the different power brick for every notebook mess.

On USB 2.0 vs. FireWire400/800: I know that this subject as been beat to death, but anyway... Higher speed are always nice, but I am not often limited by the bus speed. What I LOVE about USB is that the specification is open. Anyone can download it. You can build your own USB gizmos in your basement; no large investment is required. There are plenty of chips that support USB available in small quantities (like 1 or 2). You can even make USB look just like a serial port, making said gizmos compatable with LABView with no driver fuss. Try that with FireWire! Now if I could make all my little lab gizmos powered off the USB bus as well, heck, I might never go home.

I know FireWire is popular for video transfer, but isn't that what DVI is for? For data transfer, you don't have to run DVI in real time, and you can run 3.9 Gbits/sec over DVI today.

Hooking up a DVI cable to a video camera wouldn't be very size efficient. And there'd be no audio transfer, so while HDMI would be better, the Firewire camera protocol isn't just sending video like a monitor does, it's actually sending the raw video (kind of like how HDTV sends MPEG2 over the air) as well as support for bidirectional communication other than video, like playback commands and tape position, for example.

Powered USB sounds like a mess. But I wouldn't count those people out. Keep in mind that USB 1.0 looked like it was never going to make it compared to FireWire.Furthermore, with wireless USB, the whole thing is up in the air: wireless data with wired power may well be a better way to go overall, and Powered USB may simply not be aimed at the consumer at all.

Incidentally, the set of FireWire-powered devices seems similar to the set of USB-powered devices, meaning that the higher power available from FireWi

Furthermore, with wireless USB, the whole thing is up in the air: wireless data with wired power may well be a better way to go overall, and Powered USB may simply not be aimed at the consumer at all.

I have to disagree with you on the wireless USB point.

What does it give you that Bluetooth or Wi-fi doesn't? There have been a number of devices with some form of wireless data transfer (pdas, cell phones, etc) for years now, but they've not really taken off. Bluetooth has been most effective when used in wireless headsets, and maybe wireless keyboards and mice. For anything else (such as wireless synchronization), running the radio just drains the already short battery life of the device, meaning yo

When I saw the subject, I thought this might be about another problem that I have been considering: wall power sockets for small gadgets. It seems somewhat inefficient to take the 12v output of a solar array or mini wind turbine then invert this to mains voltage (230v over here / 110v in North America) then send this out to (large) wall sockets and plug in a wall-wart to bring it back to 12v or lower.I had assumed that there were basically two options available: high current, but ugly, car "cigarette-lighte

It's not that AC is safer at high voltages - both will kill you. It's more that you can easily transform one voltage into another using AC. This allows the use of large centralised power stations generating at high voltage and then stepping down as required. It's not easy to do that with DC. DC power needs to be generated at the voltage you will be using it at, limiting the length of the wires that can be used and forcing you to use a lot of small generators instead of one big one.Having said that, a system

... to succeed: For the same reason there is are NO standards for external power bricks for laptops/printers/scanners/hubs etc. Because there is a high margin add-on market from manufacturers to replace proprietary power devices (when lost) with expensive branded units which are probably about 5x to 10x the cost of what generic units would if there was a some common defined types (V/ma/connector-types) which would be universal. A move to efficent USB power would undercut this business in the same way, so the only standard that will be agreed upon will be an unworkable one. Firewire never replaced USB because it had licence encumberences (cost more to use), alas.

"For the same reason there is are NO standards for external power bricks for laptops/printers/scanners/hubs etc. Because there is a high margin add-on market from manufacturers to replace proprietary power devices."Not to be contrary... but don't you think manufacturers would prefer not to have to include those expensive (and heavy) bricks in the first place? Smaller packaging, lighter, which reduces shipping costs, fewer parts to order, manage, inventory, and build, less support, all translate into reduced

The cell phone industry is proving that to be wrong. It used to be that Motorola had different PSUs for each model. Now, they just have one PSU that can power any phone using the USB standard. This trend is growing fast among other manufactures too.

For the same reason there is are NO standards for external power bricks for laptops/printers/scanners/hubs etc.

USB power is no guarantee of compatibility, either. My first MP3 could be charged via a powered USB2.0 hub (no computer required); not so my iPod. I bought a USB car adapter that's iPod compatible; it charges the iPod as advertised, but not my mobile phone.

I'm not entirely sure that I can take an article seriously that asserts the IBM PC was the "first home computer that took off". Firstly, it too expensive to even be considered a home computer. I think the first home computer that took off in the US was probably the Commodore 64. In Britain and most of Europe, the first home computer that took off was probably the Sinclair Spectrum. The PC didn't take off until much, much later as a home computer - really, not until the early 1990s (by which time, we were already on the second generation of home computers to take off, the Amiga and ST, and to a lesser extent, updated versions of the Spectrum and BBC Micro)

You could argue whether the IBM PC gets first billing, or the Apple II, or the Commodore 64, I suppose; depends a lot on what you mean by "took off". But his discussion of busses also talks about USB like it was the first of its kind, a radical idea appearing out of nowhere.

Apple's Macintoshes did the same thing with Appletalk a decade earlier, probably the most successful peripheral bus, though of course it was too slow for later applications.

USB has a standard voltage of: 5VDCThe standard current associated with that voltage is: 500mA

By ohm's law:P = IV5 V *.500 A = 2.5 Watts

Even if the specification is increased to 1 A or 2 A, you still have a problem with many things like hard drives requiring 12V and 5V inputs. You can make 5V into 12V, it just costs a lot of space and money.

Actually, DC to DC voltage conversion is cheap and small (and efficient) these days, thanks to IC switching PSU controllers. Only big part left is just the coil (which is still fairly small).With regard to the article, it looks like the new Powered USB spec is a designed-by-committee mess, trying to do too many different things. I think they should just put a stake in ground for a single power output spec (and single plug) that supports most applications and not worry about the rest (high powered items).

1) It will succeed-no matter how worthless-because it will allow H/W companies to sell us everything again, including new computers and peripherals. S/W companies will find a way to take advantage of it, too.

2) It will succeed-no matter how buggy-because it will be crammed down as many throats as possible, like VISTA.

In sum, it will succeed-no matter how worthless or buggy-because it affords S/W and H/W companies yet another GOLDEN OPPORTUNIY to pump other companies' and ordinary people's bank accoun

There are some other reasons why USB was adopted so widely. First off, it was hotplug. All the other ports like PS/2, Serial and Paralell required you to restart your computer if you wanted to change what was plugged in. USB finally allowed you to change devices while the computer was on. Imagine iPods or thumb drives if USB was not hotplug!

The other advantage of USB was that the plug is simple. It's just a rectangle that goes in a rectangular hole. You can't put it in backwards. There are no screws to hold it in. It's very approachable. Unlike serial, paralell or game ports, which look like they belong in the back of the computer and not the front, USBs are safe to put on the front of just about anything. The design of the port itself invites people to use it, rather than scare them away.

These are the other reasons USB is awesome, and also yet more reasons why Powered USB will not work. Adding any sort of extra plug will just make USB scary again. The only way I see powered USB working is if you find a way to transmit that power with a connector that is identical to the existing USB port.

theres this girl I like and I really want to eat her out. I could spend hours pleasuring her. How do I ask her?

Register for callbacks on device enumeration.

Once she has enumerated, check her device descriptor bDeviceClass for class USB_HUMAN and bDeviceSubClass for HETEROSEXUAL_WOMAN. These steps are very important, do not omit them. If these are zeros in the Device Descriptor, iterate through all the Interface Descriptors. Note, if there is more than one Interface Descriptor, it may be best to skip the device.

Now send a class request, SET_FEATURE ( HUMAN_ORAL_SEX ). If she doesn't stall the request, you are good to go. Some targets have a bug where the request are stalled incorrectly a few times. In this case, you should retry a few times, but not too many, unless BUILD_OPTION_EMO_LOSER is defined in which case you should retry an unlimited number of times until the OS bugchecks. Actually, if that is defined, you can skip the class and subclass post enumeration checks too.

Powered USB hubs. That's what runs my keyboard, webcam, and scanner. In fact nothing that really requires power is hooked into the comp directly(because all that is connected directly has external power supply). The power brick is really tiny too for it. I was surprised as hell that my scanner was USB only powered.

Mostly amount of power. DVD drives, some harddrives, laptops could be driven off the USB power, but they're not, they require a separate add on plug. It's not a bad idea, though I picture it a bit like christmas lights, someone plugging in a chain of 100 different items and wondering why their PSU is smoking. (Yes I realize that's an easy thing to avoid, but it's still how I picture it)

If you'd have bothered to read the article carefully, you'd see that "Powered USB" is a different standard then USB 2.0 (which is what your Sansa uses), with different cables and higher power output. "Regular USB" is fine for powering small devices, like your Sansa. Powered USB is meant to power big devices, like printers, scanners, external hard drive enclosures and optical drives. (Sure, the minority of external hard drive enclosures are powered by USB 2.0, but it isn't recommended, which is why most e

There already is a specification that meets the requirements that Powered USB attempts to satisfy - it's called Firewire.

True, but if you are selling your product at Best Buy, you can be safe to say that most people have USB, but the majority won't have firewire.

Of course, if you want to get complicated you could provide both USB and Firewire ports and include an wall wart in the box and say "If you have USB, use the wall wart, but if you have firewire you don't need it!", but I think that would lead to a